JPS6236669B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing vinegar, particularly a method for producing vinegar with a high acetic acid concentration of 20% or more by semi-continuous fermentation using an aerated fermentation method. In the present invention, unless otherwise specified, the acetic acid concentration is expressed in weight/volume, and the alcohol concentration is expressed in volume/volume. Conventionally, various efforts have been made to obtain vinegar with a high acetic acid concentration by the aerated fermentation method. For example, in the method of JP-A No. 52-15899, vinegar with a high acetic acid concentration is obtained by a semi-continuous fermentation method devised regarding the addition of alcohol;
Methods such as No. 41495 and JP-A-53-44696 attempt to solve this problem by separating the growth tank and the bioacid tank. However, in the semi-continuous fermentation method, a portion of the moromi is used as seed vinegar for the next fermentation, which naturally limits the acetic acid concentration. Even if fermentation is carried out to a high acetic acid concentration in a raw acid tank, the higher the acetic acid concentration in acetic acid fermentation, the more inhibited acetic acid, which is the main product, will occur for acetic acid bacteria. However, there is still no example of producing vinegar with a high acetic acid concentration of 20% or more economically using the aerated fermentation method, and in this respect, there is still room for improvement. The purpose of the present invention is to overcome the drawbacks of these conventional methods and efficiently produce table vinegar having a high acetic acid concentration of 20% or more by performing semi-continuous fermentation using an aerated fermentation method. In the present invention, an aerated fermentation tank is filled with alcohol, water, acetic acid fermentation liquid or acetic acid, and a moromi prepared using nutrients for acetic acid bacteria, inoculated with acetic acid bacteria that have been acclimated to an acetic acid concentration of 15% or more, and then fermented under aeration. Fermentation is started, and when the fermentation progresses and the acetic acid concentration in the moromi rises to a sufficient level and the alcohol concentration reaches 0.7 to 2%, without interrupting aeration, leave part of the moromi and take out the rest, and then remove the raw moromi. In the semi-continuous fermentation method, which repeats the cycle by refilling the moromi to continue fermentation, then taking out a portion of the moromi in the same manner, and then refilling the raw moromi, the acetic acid concentration of the moromi increases. The temperature of the moromi is set at 27-32℃ until it reaches 12-15%, and then the temperature of the moromi is lowered to below 27℃ with 18℃ as the lower limit, and the target acetic acid concentration and alcohol concentration are 20% or more. When the concentration reaches 0.7 to 2%, leave some of the moromi and take out the rest without interrupting the aeration, then refill the raw moromi and continue fermentation in the same way as the previous cycle, and repeat the same cycle again. This method of producing vinegar is characterized by obtaining an acetic acid fermentation liquid having a high acetic acid concentration of 20% or more by performing semi-continuous fermentation using an aerated fermentation method by repeating the steps. The present invention will be explained in detail below. Conventionally, when producing vinegar using the aerated fermentation method, although the methods vary, the fermentation temperature range is 26-40℃ throughout the fermentation period, usually 28℃.
Temperatures of ~32°C have been employed. This temperature condition has been set as the optimum temperature for the production of vinegar by the aerated fermentation method, and has also been considered important in order to minimize changes in the environment for acetic acid bacteria. However, the present inventors discovered that in acetic acid fermentation under aeration, the acetic acid bacteria used have two periods during which they grow together with the bioacid (hereinafter referred to as the "growth phase") and a period during which they stop growing and continue to produce only the bioacid (hereinafter referred to as "the growth phase"). We believe that keeping the temperature the same throughout these two periods is the main reason why it has been difficult to reach high acetic acid concentrations in the past. That is, as a result of various studies focusing on the characteristics of this acetic acid bacterium, the present inventors first discovered that the optimum temperature is different during the growth phase and the bioacidic phase, and based on this, the optimum temperature is different during the growth phase. , a vinegar manufacturing method in which the temperature of the moromi is set at 27 to 32°C, which is conventionally known, and then the temperature of the moromi is lower than the temperature during the growth stage, that is, 18 to 24°C (patent application 1973). -14216 (Special Publication No. 56-21389)), production of vinegar that lowers the temperature of the moromi within a range not exceeding 2°C as the acetic acid concentration increases when lowering the temperature of the moromi during the bioacid period. Law (Special application 1977-129891)
(Japanese Unexamined Patent Publication No. 56-55193)), and a method for producing vinegar that combines aerated fermentation in which the temperature of the moromi is lowered during the acid stage and a semi-continuous fermentation method using aerated fermentation (Japanese Patent Application No. 54-136373). (Japanese Unexamined Patent Publication No. 56-61987)). After that, we continued various studies on the acetic acid bacteria used for fermentation, the alcohol concentration at the time of taking out the moromi in the semi-continuous fermentation cycle, and the temperature setting of the moromi, and finally achieved over 20% in the semi-continuous fermentation method using aerated fermentation. The present invention has been achieved, which makes it possible to obtain an acetic acid fermentation solution having a high acetic acid concentration. First, the results of a study on acetic acid bacteria used for fermentation will be explained using experimental examples. Experimental Example 1 Refilling the aerated fermentation tank with alcohol, water, acetic acid fermentation liquid, and moromi prepared using acetic acid bacteria nutrients,
When the temperature inside the tank reached 30°C, acetic acid bacteria were inoculated and fermentation was started under ventilation, and the temperature of the moromi was then controlled at approximately 30°C using a temperature controller. At that time, the acetic acid concentration was 6.5% and the alcohol concentration was 3.5%. When fermentation progressed and the acetic acid concentration reached 8.8%, addition of alcohol with an alcohol concentration of approximately 50% was started. Fermentation progresses further and the acetic acid concentration is approximately 13
%, change the setting of the temperature controller and set it to 26℃.
After that, the acetic acid concentration will be about 15%, about 17%, and about 19%.
Set the temperature controller to 24℃, 22℃, and 20℃ respectively.
When the acetic acid concentration reached 20.5%, part of the moromi was left behind and the rest was taken out, the raw moromi was refilled, and the next cycle of fermentation was started, and the fermentation was continued in the same way as the previous cycle. In this case, acetic acid bacteria in a fermenter carrying out the following fermentation were used as the acetic acid bacteria, and the effect of this on fermentation was investigated. The results are shown in Table 1. Category A: Continuous fermentation is carried out at an acetic acid concentration of 6%.Acetic acid bacteria category B: Semi-continuous fermentation is carried out at an acetic acid concentration of 12-13%.Acetic acid bacteria category C: Semi-continuous fermentation is carried out at an acetic acid concentration of 15-16%. Category D of acetic acid bacteria: Acetic acid bacteria that perform semi-continuous fermentation at an acetic acid concentration of 12 to 13%, and occasionally perform a cycle of removing the mash at a concentration of 15 to 16%.

[Table] From the results of the above experiments, it was found that if the acetic acid bacteria are capable of acetic acid fermentation under aeration by lowering the temperature of the moromi during the raw acid stage, they can ferment to an acetic acid concentration of 20% or more through aeration fermentation. It was found that being able to ferment again to an acetic acid concentration of 20% or more after refilling the raw mash, that is, being able to continue a semi-continuous fermentation cycle, is only possible by using acetic acid bacteria that have been acclimated to at least an acetic acid concentration of 15% or more. . As mentioned above, in the present invention, the selection of the acetic acid bacteria used is important, but in general, when performing semi-continuous fermentation using the aerated fermentation method, if the alcohol concentration of the moromi to be taken out is close to 0, It is known that it causes severe damage to acetic acid bacteria and stops fermentation, and on the other hand, it is economically disadvantageous to remove the moromi with a large amount of alcohol left behind, so the concentration is approximately 0.3. ~0.5% is considered appropriate. However, the present inventors conducted the following experiments and determined how to improve the quality of the moromi at the time of taking out the moromi in order to efficiently carry out semi-continuous fermentation using the aerated fermentation method, which can obtain an acetic acid fermentation liquid having an acetic acid concentration of 20% or more. We investigated the alcohol concentration of Experimental Example 2 An aerated fermentation tank similar to that used in Experimental Example 1 was filled with moromi prepared using alcohol, water, acetic acid fermentation liquid, and nutrients for acetic acid bacteria, and the acetic acid concentration was 15%.
We inoculated acetic acid bacteria that were undergoing semi-continuous fermentation on a stand, and started fermentation under ventilation.While adding alcohol and adjusting the temperature of the moromi in the same manner as in Experimental Example 1,
When the acetic acid concentration reached 20% or more, without interrupting aeration, part of the moromi was left and the rest was taken out, the raw moromi was refilled, and fermentation was continued in the same way as in the previous cycle. The alcohol concentration at the time of taking out the moromi was varied and the effect of this on fermentation was investigated. The results are shown in Table 2.

【table】

[Table] From the results of the above experiments, it was found that removing the moromi and refilling the raw moromi at an alcohol concentration of less than 0.7%, that is, the conventionally known alcohol concentration of 0.5% or less, is the best way to continue semi-continuous fermentation. Although it is possible, it was found that the average bioacid rate is low, in other words, it takes a long time for fermentation, and it is inefficient. On the other hand, if the alcohol concentration at the time of taking out the moromi is 2% or more, there is no advantage because the amount of alcohol added will be larger than others, which will affect fermentation. Therefore, the acetic acid concentration is 20%
In carrying out semi-continuous fermentation using the aerated fermentation method that can obtain an acetic acid fermentation liquid having the above,
It was found that it is appropriate to set the alcohol concentration at the time of taking out the moromi from 0.7 to 2%. Next, in the semi-continuous fermentation of the present invention, in order to obtain an acetic acid fermentation liquid having an acetic acid concentration of 20% or more,
During the growth phase (that is, until the acetic acid concentration in the moromi reaches 12-15%), the temperature of the moromi is kept at 27-32℃, but after the acetic acid concentration reaches 12-15%, the lower limit is 18℃. It is important to reduce the temperature to below 27°C. This point will be explained using an experimental example. Experimental Example 3 An aerated fermentation tank similar to that used in Experimental Example 1 was filled with moromi prepared using alcohol, water, acetic acid fermentation liquid, and nutrients for acetic acid bacteria, and when the temperature inside the tank reached 30°C. After inoculating the acetic acid bacteria that were performing semi-continuous fermentation at an acetic acid concentration of 15%, fermentation was started under aeration, and the temperature of the moromi was then controlled at approximately 30°C using a temperature controller. At that time, the acetic acid concentration was 6.8% and the alcohol concentration was 3.2%. When the fermentation progresses and the acetic acid concentration reaches 8.5%, the addition of alcohol with an alcohol concentration of approximately 50% is started, and as the acetic acid concentration increases, the settings of the temperature controller that controls the temperature of the moromi are changed. As a result, the temperature of the moromi was lowered to 26℃. At this time, the acetic acid concentration at the time when the temperature started to be lowered was varied, and the average bioacid rate for 4 hours before reaching the acetic acid concentration and 4 hours after reaching the acetic acid concentration was investigated. The results are shown in Table 3. Note that the average bioacid rates A and B in Table 3 were calculated using the following formula. A=X-Y/4 B=Z-X/4 Acetic acid concentration after time (%)

[Table] From the results of this experiment, it is clear that if the temperature starts to decrease when the acetic acid concentration in the moromi is 12 to 15%, preferably 12 to 13%, it has little effect on the rate of bioacid; It can be seen that the appropriate acetic acid concentration is 12 to 15%, preferably 12 to 13%, when the concentration of acetic acid begins to decrease. Furthermore, by conducting the following experiment, we investigated the final set temperature of the moromi, that is, the temperature at the time of taking out the moromi. Experimental Example 4 An aerated fermentation tank similar to that used in Experimental Example 1 was filled with moromi prepared using alcohol, water, acetic acid fermentation liquid, and nutrients for acetic acid bacteria, and when the temperature inside the tank reached 30°C, Acetic acid bacteria, which are performing semi-continuous fermentation at an acetic acid concentration of 15%, were inoculated and fermentation was started under aeration, after which the temperature of the moromi was controlled at approximately 30°C using a temperature controller. At that time, the acetic acid concentration was 6.8% and the alcohol concentration was 3.6%. When the fermentation progressed and the acetic acid concentration reached 8.5%, addition of alcohol as described in Experimental Example 1 was started. When the fermentation progressed further and the acetic acid concentration reached approximately 13%, the temperature controller was changed to 26℃, and from then on the acetic acid concentration increased to approximately 15% and approximately 17%.
%, about 19%, change the setting of the temperature controller to lower the temperature of the moromi, and when the acetic acid concentration reaches 20% or more, leave some of the moromi without interrupting the aeration and remove the rest. The fermentation was then carried out in the same manner as in the previous cycle, and the next cycle of fermentation was continued. While repeating the cycle in the same manner, the temperature set when the acetic acid concentration was about 19%, that is, the temperature at the time of taking out the moromi, was varied, and the influence on the next cycle was investigated. The results are shown in Table 4.

[Table] From the results of this experiment, when the final temperature is lower than 18℃, an induction period occurs at the beginning of the next cycle, and although the acetic acid concentration reaches 20℃ or higher, the average bioacid rate is low, in other words, the fermentation time is longer. Since the efficiency deteriorates as the temperature ages, it is clear that a lower limit of the temperature of the moromi is 18°C. In the present invention, fermentation is started under aeration using acetic acid bacteria that have been acclimated to an acetic acid concentration of 15% or more as described above, and the temperature of the moromi is kept at 27°C until the acetic acid concentration of the moromi reaches 12 to 15%.
~32℃, then lower the temperature of the moromi to 18℃.
Semi-continuous fermentation is carried out by lowering the temperature to below 27°C, and when the acetic acid concentration reaches 20% or more and the alcohol concentration reaches 0.7 to 2%, the moromi is taken out and the raw moromi is refilled, and fermentation is continued in the same way. Other than the above, it can be carried out in accordance with the conventional production of vinegar by the aerated fermentation method. That is, as the moromi, a moromi prepared with alcohol, water, acetic acid fermentation liquid or acetic acid, and nutrients for acetic acid bacteria (for example, a suitable one among sake lees infusion, yeast extract, inorganic salts, sugars, and organic acids) is used.
In the aerated fermentation tank where fermentation takes place, alcohol, the main raw material, and acetic acid, the main product, are both volatile, so a relatively small amount of aeration (for example, 5 to 30% of the mash content per minute) is necessary to ensure sufficient mixing. A tank (for example, an aerated stirring type fermenter, an air lift type fermenter, a gas entrainment type culture apparatus, etc.) is used. Furthermore, inoculation of acetic acid bacteria and aging, filtration, and sterilization of the acetic acid fermentation liquid to make vinegar after completion of fermentation can be carried out according to conventional methods. Thus, according to the present invention, it is possible to efficiently obtain an acetic acid fermentation liquid having a high acetic acid concentration of 20% or more by semi-continuous fermentation using the aerated fermentation method, and this acetic acid fermentation liquid is aged, filtered, and sterilized by conventional methods. It is possible to produce vinegar with a high acetic acid concentration of 20% or more. Moreover, in the present invention, since semi-continuous fermentation can be performed, only one fermenter is required, and there is no need to separate it into a growth tank and a raw acid tank, and fermentation can be carried out efficiently. This is a very useful method for producing vinegar by aerated fermentation. Next, examples of the present invention will be shown. Example: A full-capacity unit equipped with a stirring blade, temperature control coil, and defoamer to finely pulverize air introduced from the outside and disperse it into the liquid in the tank, and connected to an air flow meter.
Denatured alcohol in a 25000 aerated fermentation tank,
Water, unfiltered white vinegar, sugar, inorganic salts,
A 14,000 mash with an acetic acid concentration of 6.8% and an alcohol concentration of 3.2% prepared by mixing nutrients such as yeast extract was prepared, and aeration stirring was started at an aeration rate of approximately 2,000 m/min. When the temperature of the moromi reached 30℃. The temperature controller was operated to maintain the temperature of the moromi at 29.8-30.2°C. Meanwhile, a fermentation tank similar to the one above with a total capacity of 20,000 liters was charged with moromi made from the same raw materials as above, and while semi-continuous fermentation was being carried out at an acetic acid concentration of 15%, refilling of the raw material moromi was completed. After that, when the acetic acid concentration reached about 7%, this moromi 2000 was rapidly pumped to the above level using a self-contained pump without interrupting the aeration.
The moromi in a 25,000 aerated fermentation tank was inoculated. At this time, the alcohol concentration of the inoculated moromi was approximately 3.5%. The acetic acid concentration and alcohol concentration of the moromi in the inoculated aerated fermentation tank were 6.82% and 3.68%, respectively. Five hours after inoculation, the acetic acid concentration increased by 0.54%, indicating that the induction period was short and fermentation had started. 7 more
After a period of time, when the acetic acid concentration reached 8.5% and the alcohol concentration reached 1.9%, addition of denatured alcohol having an alcohol concentration of about 50% was started. 18 hours after starting the addition of alcohol, the acetic acid concentration reached 12.8%, so the temperature controller was set to 26.
℃. After that, the temperature controller was set to 24℃, 22℃, and 20℃ at the 12th, 25th, and 40th hours, respectively, and the acetic acid concentration after that was 15.3% and 20℃, respectively.
They were 17.2% and 19.3%. Furthermore, at the 50th hour, the acetic acid concentration was 20.5% and the alcohol concentration was 2.0%, so the addition of alcohol was stopped, but at this point the total volume of the moromi was about 23,000. Further fermentation continued, and at 59 hours after starting to change the temperature controller settings, the acetic acid concentration was 21.5% and the alcohol concentration was 1%. Therefore, approximately 18,500 mash was taken out without interrupting the aeration, and newly denatured alcohol was added. ,
At the same time as we started filling approximately 11,500 ml of raw material moromi with an acetic acid concentration of 1% and an alcohol concentration of 5%, consisting of nutrients such as water, unfiltered white negative, sugar, inorganic salts, and yeast extract, we changed the settings of the temperature controller. The temperature was set at 30℃. After refilling the raw mash, the acetic acid concentration was 6.77% and the alcohol concentration was 3.88%. Thirteen hours after refilling the raw mash, the acetic acid concentration was 8.6% and the alcohol concentration was 2%, so addition of denatured alcohol was started in the same way as in the previous cycle. After that, as in the previous cycle, the acetic acid concentration was 13.2%, 15.4%, 18.0%,
At 19.1%, the temperature controller settings were changed to 26°C, 24°C, 22°C, and 20°C, respectively. 68 hours after starting the addition of denatured alcohol, the acetic acid concentration was 20.6% and the alcohol concentration was 1.9%, so the addition of denatured alcohol was stopped, but at this point the total volume of the moromi was approximately 23,000. . Fermentation continued, and 77 hours after starting the addition of denatured alcohol, the acetic acid concentration was 21.6% and the alcohol concentration was 0.9%, so we removed the moromi, refilled the raw moromi, and The settings of the temperature controller were changed, and the same operations as described above were performed to continue fermentation. By repeating such a cycle, an acetic acid fermentation liquid having a high acetic acid concentration of 20% or more was obtained by a semi-continuous fermentation method, and this was aged, filtered and sterilized to obtain vinegar with a high acetic acid concentration.

Claims (1)

[Claims] 1 Fill an aerated fermentation tank with alcohol, water, acetic acid fermentation liquid or acetic acid, and a moromi prepared using nutrients for acetic acid bacteria, inoculate with acetic acid bacteria that have been acclimated to an acetic acid concentration of 15% or more, and ferment under aeration. After fermentation has progressed and the acetic acid concentration in the moromi has increased sufficiently and the alcohol concentration has reached 0.7 to 2%, without interrupting the aeration, leave part of the moromi and take out the rest, and then refill the raw moromi. In successive cycles of the semi-continuous fermentation method, in which a part of the moromi is taken out in the same manner and then refilled with the raw moromi, the cycle is repeated, the acetic acid concentration of the moromi reaches 12 The temperature of the moromi is set at 27 to 32℃ until it reaches ~15%, and then the temperature of the moromi is lowered to below 27℃ with 18℃ as the lower limit, and the target acetic acid concentration and alcohol concentration are 0.7 to 20%. When it reaches 2%, leave some of the moromi and take out the rest without interrupting the aeration, then refill the raw moromi and continue fermentation in the same way as the previous cycle, and repeat the same cycle. A method for producing table vinegar, characterized in that an acetic acid fermentation liquid having a high acetic acid concentration of 20% or more is obtained by performing semi-continuous fermentation using an aerated fermentation method.